<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<button>按钮</button>
<p>hello world</p>
<script type="text/javascript">
    function transformRegular(a){
        return a.replace(/\s/,'-')
    }
    alert(transformRegular('hello world'))
//    邮箱验证  一串英文、数字、下划线   @一串英文、数字   .一串英文
//               \w+                 @[a-z0-9]+      \.[a-z]+

</script>
</body>
</html>